Stoker



1944- J. s. BENNETT STOKER Filed July 30, 1940 4 Sheets-Sheet l I [tn/511T UR JUEEPH 5.5ETITIETT Oct. 31, 1944. J. s. BENNETT 2,361,736 7 STOKER Filed July so, 1940 4 Sheets-Sheet 2 ITIUETITEJR JUEEFJW 5. EETmETT 93 B ATTUFQHQY Oct. 31, 1944. J. BENNETT I v 2,361,736

STOKER Filed July 30, 1940 4 Sheets-Sheet 4 FI -E I 15.9

. Im/EHTIJR JugEPh 5. BENNETT ATTEIRTI Y Patented Oct. 31, 1944 STOKER Josephfi. Bennett, Merion, Pa., assignor, by mesne assignments, to American Engineering Company, Philadelphia, Pa.,

Pennsylvania a corporation of Application July 30, 1940., Serial No. 348,397

' '10 Claims.

invention relates to stokers, and more particularly to stokers .of the multiple :retort underfeed type. t

One object of the present invention .is to provide a generallvimprovedstoker which is simple in construction :and highly efficient in operation.

Another object is to provide :in a :stoker of the class described an improved dump grate con-- struction which functions to feed the ashes through a discharge opening. the .dump grate being provided with a flexible supportwhich senables downward movement thereof to permit large clinkers to pass through the discharge openings.

Another object is to provide in a \stoker f the class described a new pusher arrangement for l underfeeding the fuel along the stoker.

A further object is to provide certain novel .details of construction which simplify, the structure of the stoker as a whole.

Other and further objects will :become apparent as the description of the invention progresses.

Of the drawings:

Fig. 1 is a longitudinal sectional view taken through one of the retorts of the stoker comprising the present invention.

Fig. 2 is a side view, partly in section, of the lower end of the stoker showing the improved dump grate construction forming a part of the present invention.

Fig. 3 is a sectional view taken substantially along line 3--3 of Fig. 2. a

Fig. 4 is a side view partly in section of the upper end of the stoker showing the improved ram box construction associated therewith.

Fig. 5 is an elevational view partly in section taken substantially along line 5--5 of Fig. 4.

Fig. 6 is a sectional view taken substantially along line 6-5 of Fig. 4. d

Fig. 7 is a fragmentary view partly in section, showing the construction of one of the pushers provided in the retorts of the stoker.

Fig. 8 is a sectional view taken substantially along line 88 of Fig. 7.

Fig. 9 is a sectional view taken substantially along line 9-9 of Fig. '7.

Fig. 10 is a longitudinal sectional view take substantially along line l'0 lll of Fig. 7.

Fig. 11 is an end view taken substantially along line |l-H of Fig. 1.

Fig. 12 is a sectional end view taken substantially along line I2--|2 of Fig. 4, and

Fig. 13 is a longitudinal sectional view of a modified form of pusher construction.

Referring to the drawings, the numeral I designates a furnace having a stoker 2 mounted therein. Stoker 2 com-prises alternately disposed retorts 3 and tuyene rows 4, and inclines downwardly and rearwardly from the front wall 50f the furnace. Fuel from hoppers 6 is fed to the retorts 3 :by rams 1 through openings .8 provided in wall '5 in the usual manner. Rams I may be operated by any suitable power mechanism indicated generally at 9. The bottom of each retort of the illustrated stoker has provided therein an upper pusher I ll, an inter-mediate dead plate II, a lower pusher l2, and an air cooled .dead plate l3. A fuel supporting plate 14 forms the bottom of each opening .8 and extends into the retort directly above upper pusher Ill. The pushers L0 and l2 underfeed the fuel along the retorts toextension grates 1-5, which in turn feed the fuel and ashes to a reciprocatory dump grate 16. From dump grate 18 the. ashes are fed through a discharge passage 41 defined at the bottom thereof by the dump grates l6 and at the top by the lower portion 18 of the rear wall IQ of the furnace.

When the terms front and rear are used herein itis to be understood that the term front indicates the portion of an element extending toward the front wall 5, and the term 'rear relates to the portion of the element extending toward the rear wall 19. a

The upper pusher I0 has secured to the forwardly disposed end thereof a bracket 20 to the upper end of which a slidable operating rod 2| is secured in any suitable manner. Rod 2| extends through an aperture provided in the plate 22 of the stoker front '23 and has pivotally connected to its outer clevised end a second rod 2,4. Rod 24 has mounted thereon a sleeve 215 to which is pivotally connected an actuating lever 26. Lever 26 is pivoted intermediate its ends to a fixed bracket 21 secured to and extending outwardly from the stoker front 23. The upper end of lever 26 is pivotally attached to the forwardly disposed end of feeding ram 1 while the lower end thereof is pivotally connected to a sleeve 28 mounted on a rod 29, which rod in turn is pivotally connected toa second rod 30 slidably mounted in stoker front 23. The left hand end fFig. 1) of rod 30 is pivotally connected to a connecting rod 3| which in turn is connected to a member 32 which extends through'an enlarged. aperture provided in the vertical partitionmember 33 disposed beneath the lower ,end of stoker i Member 32, as shown in Fig. 1, is pivota ly attached to theframework 15 of extension grate 15. Up-

per and lower pushers l and 12 are connected for simultaneous operation by a rod 34.

From the foregoing description it is seen that upon operation of rams l by the power mechanism 9 lever 25 is caused to move about its pivotal connection on bracket 2], thereby simultaneously actuating'pushe'rs Ill and i2 and extension grate l5. The usual removable washers 35 and 59 are provided on rods 24 and 29 respectively, near the right hand ends thereof (Fig. 1) whereby the extent of movement of pushers l9 and I2 and extension grates l5 may be varied. Similar removable'washers 9! may be placed on rod 34 to permit relative movement of pushers ill and I2 and to vary such relative movement.

The right hand end of member 32 has also Ipivotally attached thereto the upper end of a lever 38. Lever 36 is pivoted at the lower end thereof, as shown at 36, and has pivotally mounted intermediate its ends a collar 39 slidably mounted on a rod 49 between fixed abutments 39 and 39 secured to rod 4!]. Rod 40 is pivotally connected at the left hand end thereof to an operating member 4! for the dump grates l6. Accordingly, upon actuation of lever 26 by the rams I, as previously described, dumpgrates It will be simultaneously operated. A series of removable washers 39 may be placed on rod 40 between collar 39 and abutment 39 whereby the extent of movement of dump grate It may be varied.

Air for combustion purposes is supplied to the furnace from a plenum chamber 42 disposed beneath the stoker, which in turn receives air under pressure from any suitable fan or blower mechanism (not shown) through a passage 43.

As shown in Fig. 1, fluid conducting tubes 14 extend vertically along the inner surface of the front wall 5, and thence over the tuyere rows 4 and the portions of the extension grates I5 in will be observed upon reference to Fig. 1, receives the ashes fed from the stoker through discharge I passage 11.

Referring more particularly to Figs. 1 and 2,

it will be seen that each operating member 4| has secured to the left hand end thereof an enlarged rectangular portion 68 which extends between the lower surface of air cooled member 49 and a bearing member 69 secured in any suitable manner to the side plates 59 near the lower ends thereof. The left hand end of rectangular portion 68 is pivoted at 10 to the right hand end of dump grate [5. As shown more particularly in Fig. 3, the dump grates 16 in the present instance are made up of independently operable sections, each consisting of three interconnected members H, 12 and 13. Member H consists of an upper serrated fuel and ash supporting portion 14, having a relatively short flange 15 at the left side thereof (Fig. 3) and a relatively long flange 16 at the right side thereof. Element 13 is similar in construction to element 1!, except that it has a relatively short flange 1'! provided at the right side thereof, and a relatively long flange 18 at its left side, these flanges being connected by an upper serrated fuel and ash supporting portion 19. Member 12 is generally similar in: construction to members H and 13, except that it contains relatively long flanges 80 and 8| at both sides thereof, these flanges alignment therewith, and then are bent downwardly and forwardly, as shown at $5, and terminate at their lower ends in a header 46 disposed beneath the lower end of the stoker. The rear wall i9 also has provided thereon fluid conducting tubes 4T which extend vertically therealong from a header 48. Fluid maybe supplied to the headers 46 and 48 from a boiler (not shown) or from any other suitable'source. The upper ends of tubes 44 and ll may also terminate in said boiler or in headers, which in turn may be connected to any disposal means for the fluid.

As shown more particularly in Figs. 1 and 2, an air cooled stationary member 49 is disposed between extension grates l5 and dump grates IS.

The retorts 3 of the stoker 2 are bounded at the sides thereof by longitudinally extending plates 56 secured in any suitable manner-at their upper ends to brackets 5| mounted on the I- beam 52 forming a portion of the stoker front 23. A series of tuyre supporting members 53 are secured by any suitable means,"such as by bolts 54, to the upper flanges I35 of side plates 50. Supporting members 55 for ram box cap extensions 56 are also mounted on plates and are secured to the flanges 135 thereof by bolts 51. These members extend between the uppermost tuyere supporting members 53 and the brackets 51, and are also secured thereto by bolts 58. The upper flanged portion 59 of supporting members 55 and the top flat surface 60 of brackets 5| are in alignment, the former, as pointed out before, form the supports for the ram box being connected at their upper edges by a serrated fuel and ash supporting portion 82. Flanges l6 and of members H and 12 ar secured together by a bolt 83. Flanges BI and 18 of members 12 and 13, respectively, are likewise secured together by a bolt 84. A rod 86 extends through the lower ends of flanges 16, 89, 8| and :18, and has mounted thereon a roller 81 which 1s supported on the upper bearing surface 88 of a bracket 89. Rod 86 is held in position by nuts 90 provided at the opposite ends thereof.

From the foregoing description it is seen that each dump grate-section I6 is made up of three relatively narrow members. Thus, in the event that damageshould occur to any one or more of I the members H, Her 13 of a section, it is only necessary to remove the damaged member and replace it with a new one. Each section is operated by power mechanism 9 through a series of independent connections as previously described.

Brackets 89 are pivotally supported on the side plates 59 near the lower ends of the latter, as shown at 9!, andeach bracket has secured to the downwardly extending flanges 92, 92 thereof, by bolts 93, a pair of elongated plates 94, 94. The lower ends of plates 94, 94 are pivotally connected to the outer end of a tubular member 95. Tubular member 95 is provided with screw threads 96 at the right hand end thereof (Fig. 2) which make threaded engagement with the internal threads 91 provided at the ri ht hand end of a sleeve member 98. Tubular member 95 and sleeve 98 extend through an enlarged aperture 99 pro- Vided in the web I00 of I-beam 64 upon which with sleeve 98 and disposed to the right of web I of I-beam 64 is a spring seat IOI against which one end of a coil sprin 'l02 abuts. The other end of coil spring I02 engages the inner surface of a block member I03 slidably mounted on sleeve 98. A pair of channel members I04 and I05 are secured to the lower flange I06 of I-beam 64 by bolts IN or by any other suitable fastening means. The outer ends of channel members I04 and I 05 are pivotally mounted on trunnions I08 and I09 extending outwardly from block I93. By this construction it is seen that in the event of an abnormal load, such as may be caused by movement of an unusually large clinker through the discharge opening II', dump grates I 6, and consequently brackets 69, will move downwardly thereby causing plates 94, 94 toactuate tubular member 95 and sleeve 98 to the right. By this action spring seat IOI will also move'to the right. However, inasmuch as sliding block I03 is held against movement by channel members I04 and I05, spring E02 will be compressed and when the load has been relieved the spring will restore the parts to normal position. By providing the threaded tubular and sleeve members 95 and 98, the position of dump grates I6 may be varied so as to increase or decrease the siZe of the discharge passage if. The threaded portions 96 and 9'! may be lubricated by any suitable lubricating fluid supplied to the interior of tubular member 95, the fluid being retained therein by'a plug IE9. Apertures III provided in tubular member 95 permit fluid to drip into sleeve 98 and thus lubricate the threaded portions 96 and 91.

Referring more particularly to Figs. 4 to 6, it will be noted that each ram box cap 92 is provided with a substantially hollow portion I I4 hav-' ing at the bottom thereof an upwardly inclined portion II5 which extends from the plate 22 of the stoker front to the forwardly disposed edge II6 of ram box cap extension 56. A flange it; extends outwardly from each side of each ram box cap 62 and rests upon the upper surface 60 of a bracket 5|. Bolts II8 extending through flanges I I1 and the upper surfaces of brackets 5| rigidly secure the ram box caps 62 in position.

Each ram box cap extension 56 comprises an upper hollow portion H9 having an opening I at each side thereof through which air discharging from outlet openings I20 provided in air boxes I2I may enter. The air so entering chamber H9 is dischargedtherefrom into the furnace through a series of apertures I22 provided at the rearwardly disposed end thereof. Each ram box cap extension 56 has also provided at the sides thereof depending legs I23 and I24 which rest upon the upper flanges 59 of supporting plates 55. Legs I23 and I24 have provided at the inner sides thereof a pair of enlarged longitudinally aligned apertured recesses I25 and I26. Extending vertically from each flange 59 is a second flange I21 having apertures therein in alignment with the apertures provided in the recesses I25 and I26 respectively. The lower end of each side wall I28 of the air boxes I2I is also provided with apertures in substantial alignment with the apertures in flanges I21 and legs I 23 and I24 of ram box cap extension 56. Bolts I29 extending through said aligned recesses rigidly secure each ram box cap extension in position.

The portion of Fig. 5 shown in section illustrates the structure of the ram box cap extension 56 and air box I2I at the air openings I20 and I20, while the portion to the left thereof shows the structure of the inner surface of the furnace wall adjacent the stoker. It will be noted that a series of vertically disposed grid bars I30 are provided at the furnace side of the air boxes I2I. These grid bars occupy the entire inner end of each air box I 2I extending between adjoining ram box cap extensions 55. The construction of the air boxes I 2| and grid bars I30 is generally similar to those shown in United States Patent No. 1,907,066. Accordingly, a detailed description thereof may be had upon reference to said patent.

The ram box caps 62 and ram box cap extensions 56 also are generally similar in construction to those shown in United States Patent No. 1,907,066, except insofar as the fastening means are concerned. In the present instance bolts I29 are employedto rigidly secure the ram box cap extensions in position. Any suitable fire brick I3I is supported on the upper surfaces of the ram .box caps 62, ram box cap extensions 56, and the upper surfaces of air boxes I2I to complete the front wall 5. By this construction it is seen that the ram box cap extensions may be removed without disturbing the brickwork I3I. By simply removing the bolts I 29 the ram box cap extension may be moved rearwardly into the furnace and a new one may then be inserted in its place.

' The lower surface II9 of ram box cap extension 56 is inclined and is in substantial alignment with the surface II5 of ram box cap 6. These surfaces form the upper fuel deflecting portions of fuel inlet openings 3. Openings 3 are bounded at the sides by members 55 and brackets 5| and at the bottom by fuel supportin plates I4.

Upon reference to Fig. 12, it will be seen that the upper surface I32 of the flange I 53 provided at the lower end of each supporting member 53 and 55 is constructed so as to be substantially parallel to the lower surface I 34- of the flanges I35 of side plates 50. By this "construction it will be noted that the head of the bolt 54, as well as the securing nut I36, will lie flush against the surfaces I 32 and I34 respectively.

As shown more particularly in Figs. 4 and 12, members 53 and 55 have each provided thereon a series of substantially vertically and longitudinally extending vanes or ribs 53 and 55 respectively, which tend to maintain these members relatively cool during operation of the furnace.

Referring to Figs. '7 to 10 inclusive, it is seen that each pusher I0 is slidably mounted on the forward extension I9! of dead plate I I, and extends between the side plates 50 forming the side walls of a retort 3. Portion I31 of dead plate II also extends'between the side plates 50, 50 and is secured thereto by a series of bolts I38.

Pushers I0 and I2 are similar in construction, and accordingly a description of one will suflice for both. As shown more particularly -in Fig. '7, pusher I0 is made up of three sections, a forwardly disposed section I40, an intermediate section MI, and a rearwardly disposed section I42. Section I40 comprises an upper wall I43, a pair of side walls I44, a forwardly disposed wall I45, and a rear wall I46. Forwardly disposed wall I45 is secured to bracket 20 in any suitable manner,

such as by bolts I41. Rear wall I46 is secured to the forward wall I48 of intermediate section MI by bolts I49. Section I4I also has an upper wall I59, a portion of which, as shown at I5I, inclines downwardly and rearwardly and terminates in arearwardly disposed vertical walll52 which in turn is secured by bolts I53to the forward wall I54 of rear section I42. Intermediate section also comprises a pair of side walls I55, I55 having inwardly extending flanges I56, I56 provided at the lower ends thereof. Supporting portion I31 has secured thereto a retaining and guiding member I51 for pusher ID. Guide member I51 consists of a body portion I58 extending transversely of supporting portion I31 and is secured to the latter by any suitable means, such as by bolts I59. A flange I60 extends outwardly from each end of body portion I58 to overlap the flanges I56, I56 provided at the lower ends of the side walls I55, I55 of intermediate section I4I. By this construction it is seen that pusher I is prevented from tilting during its reciprocatory feeding movements. Rearwardly disposed section I42 comprises an upper inclined section I62 in substantial alignment with portion I5I of intermediate section I4! and terminates in a vertically disposed rear wall I63. Section I42 is also provided with side walls I64.

The outer surfaces of side walls I44 of forwardly disposed member I40 are provided with a series of vertically disposed ribs I65, as shown more particularly in Fig. 10. These ribs are provided to preventthe passage of fuel siftings between pusher II] and the side plates 56 of the retort 3.

Fig. 13 shows a somewhat modified pusher construction I which may be utilized to advantage in cases where it is desirable to construct pushers of difierent lengths. This construction also shows a forwardly disposed section I1I, an intermediate section I12, and a rearwardly disposed section I13. The forwardly disposed Section I1I is bolted to a bracket 20. By this arrangement additional intermediate or forwardly disposed sections I12 or I1I may be employed to obtain a pusher of the desired length.

While the embodiments herein shown and described are admirably adapted to fulfill the objects primarily stated, it is to be understood that the invention is not to be limited thereto, since it may be embodied in other forms, all coming within the scope of claims which follow.

What is claimed is:

l. A tuyre support adapted to be mounted upon the side plates of a stoker furnace, said tuyere support comprising a substantially rectangular body portion having a flange disposed along the lower edge thereof, a series of cooling vanes provided on one surface of said body portion, and said flange tapering inwardly from its free end whereby said flange has its greatest thickness at the outer end thereof, and diminishes in thickness as it approaches the body portion.

2. A tuyere support for stokers comprising a substantially rectangular body portion, a flange integral with said body portion and extending laterally from one edge thereof, said flange tapering from the free end towards its connection with the body portion whereby said flange is of greatest thickness at its outer end, and cooling means provided on said body portion.

3. In a device of the class described, the combination of dump grates adapted for assembly at one end of a stoker, means for pivotally supporting one end of said dump grates, means providing a resilient support for said dump grates, whereby said dump grates may move downwardly when subjected to abnormal loads, and

means for reciprocating said dump grates to feed the fuel andrefuse supported thereon to a place of disposal.

4. In a device of the class described, the combination of dump grates adapted for assembly at one end of a stoker, means for pivotally supporting one end of said dump grates, means providing a resilient support for said dump grates, whereby said dump grates may move downgardly when subjected to abnormal loads, means for reciprocating said dump grates to feed the fuel and refuse supported thereon to a place of disposal, and a series of vertically disposed feeding faces provided at the upper portion of said dump grates.

5. In a device of the class described, the combination of dump grates adapted for assembly at one end of a stocker, means for pivotally mounting one end of said dump grates, a support for said dump grates, anti-friction means disposed between said support and said dump grates, means for reciprocating said dump grates to feed the materials supported thereon to a place of disposal, and resilient means for said support whereby said dump grates may move downwardly when subjected to excessive loads.

6. In a device of the class described, the combination of dump grates adapted for assembly at one end of a stoker, means for pivotally supporting one end of said dump grates, and means providing a resilient support for said dump grates, whereby said dump grates may move downwardly when subjected to abnormal loads, said last mentioned means comprising a pivotally mounted bracket having a supporting portion and a depending portion, and resilient means operatively connected to said depending portion.

'7. In a device of the class described, the combination of dump grates adapted for assembly at one end of a stoker, means for pivotally supporting one end of said dump grates, and means providing a resilient support for said dump grates, whereby said dump grates may move downwardly when subjected to abnormal loads, said last mentioned means comprising a pivotally mounted bracket having a supporting portion and a depending portion and a movable member pivotally connected to said depending portion, a spring seat integral with said movable member, a spring mounted on said movable member, one end of said spring engaging said spring seat, an abutment member engaging the other end of said spring, a fixed support, and means pivotally connecting said abutmerit member to said fixed support.

8. A dump grate comprising, a middle section, and two side sections, said middle section consisting of an upper material supporting and feeding portion and a downwardly extending flange at each side of said supporting portion, each of said side sections also comprising an upper material supporting and feeding portion and a flange depending from each side of said upper portion, means for detachably securing said side sections to said middle section, an anti-friction roller disposed between the flanges of said middle section, and means extending through some of said flanges for supporting said roller.

9. A dump. grate comprising, a middle section, and two side sections, said middle section consisting of an upper material supporting and feeding portion and a downwardly extending flange at each side of said supporting portion, each of said side sections also comprising an upper material supporting and feeding portion and a flange depending from each side of said upper portion, means for detachably securing said side sections to said middle section, an anti-friction roller disposed between the flanges a flange depending from each side of said upper portions, means for detachably securing said side sections to said middle section, an anti-friction roller disposed between the flanges of said middle section, means extending throughsome of said flanges for supporting said roller, means for reciprocating said dump grate and a resilient support for said dump grate whereby the latter may move downwardly when subjected to abnormal loads, and means for reciprocating said 10 dump grate.

JOSEPH S. BENNETT. 

